Drop ejection devices are used for a variety of purposes, most commonly for printing images on various media. They are often referred to as ink jets or ink jet printers. Drop-on-demand drop ejection devices are used in many applications because of their flexibility and economy. Drop-on-demand devices eject one or more drops in response to a specific signal, usually an electrical waveform, or waveform, that may include a single pulse or multiple pulses. Different portions of a multi-pulse waveform can be selectively activated to produce the drops. One or more drive pulses build a drop and one or more break off pulses initiate the break off of the drop from a nozzle of the drop ejection device.
Drop ejection devices typically include a fluid path from a fluid supply to a nozzle path. The nozzle path terminates in a nozzle opening from which drops are ejected. Drop ejection is controlled by pressurizing fluid in the fluid path with an actuator, which may be, for example, a piezoelectric deflector, a thermal bubble jet generator, or an electrostatically deflected element. A typical printhead has an array of fluid paths with corresponding nozzle openings and associated actuators, and drop ejection from each nozzle opening can be independently controlled. In a drop-on-demand printhead, each actuator is fired to selectively eject a drop at a specific target pixel location as the printhead and a substrate are moved relative to one another. A drop's mass is distributed in the head and tail of the drop. Drop “tail” refers to the filament of fluid connecting the drop head, or leading part of the drop to the nozzle until tail break off occurs. Drop tails often travel slower than the lead portion of the drop. In some cases, drop tails can form satellites, or separate drops, that do not land at the same location as the main body of the drop. Thus, drop tails can degrade overall ejector performance.